Control system



Jan. 19 1926.

H. L. BLOOD ET AL CONTROL SYSTEM Filed August 25, 1923 Patented Jan. 19,1926..

"UNITED sT rEs PATENT OFFICE.

HAROLD L. BLOOD, OF NORTH "ELAINFIELD, AND ROBERT C. DEALE, OFPLAINFIELD, NEW JERSEY, ASSIGNORS TO NILES-BEMENT-POND COMPANY, OF NEWYORK, N. Y., A CORPORATION OF NEW JERSEY.

CONTROL SYSTEM.

Application filed August as, 1923. Serial Nb. 659,364.

To all whom it may concern:

Be it known that we, HAROLD L. Bnoon and ROBERT C. DEALE, citizens ofthe United States, and residents, respectively, of North Plainfield, inthe county of Somerset and State of New Jersey, and Plainfield, in thecounty of Union and State of New Jersey, have invented certain new anduseful Improvements in 'Cont'rolSystems, oi which the following is aspecification.

Our invention relates to control systems and particularly to controlsystems for governing the operation of machine tools.

One object of our invention is to provide a control system that shallautomatically control a feed motor and reverse the direction of rotationof such motor at each end of the stroke of a reciprocating member andthat shall control the feed motor at will while insuring againstautomatic operation thereof.

Another object of our invention is to provide a control system thatshall have a reciprocating member for automatically controlling theoperation of a main motor and a feed motor and that shall be providedwith a portable switch mechanismfor prevent-- ing automatic operation orthe main motor and the feed motor and for efiectlng operation of themotors at will.

Another object of our invention is to provide a control system of theabove indicated character that shall be provided with switches foraccelerating the main motor in a forward and in a reverse direction andfor completing a dynamic braking circuit therethrough andwith switchesfor accelerating the feed motor in a forward and in a reverse directionand for completing a dynamic braking-circuit therethrough and that shallbe provided with a portable switch mechanism for controlling the mainmotor switches and the feed motor switches atv will.

A further object of our invention is to provide a control system of theabove indicated character that shall be provided with a portable switchmechanism 7 having two switch members for respectively controlling themain and the feed motor at will and that shall he provided withinterlock switches associated with the portable switch mechanism forpreventing the automatic operationor acceleration of the main motor andthe automatic operation of the feed motor when one of the switch memberson the portable switch mechanism is moved from initial position.

In a control system motor in a forward and in a reverse direc tron andfor-completing a dynamic braking constructed in accordance'with ourinvention, two main SWlllOllQS' circuit therethrough. An acceleratingswitch is provided for governing the acceleration of the feed motor. Themain and the feed motors are automatically controlled in accordance withthe movement of a reciprocating member as for example the reciprocatingtable of a planer. lihe feed motor and the main motor are not onlycontrolled automatically by a pilot switch but are controlled at will bymeans of a portable switch mechanism having two switch members. One ofthe switch members serves to control the feed motor and the otherswitchserves to control the main motor. Each of the switch members is providedwith interlock switches to prevent the automatic operation of either ofthe motors and to prevent the acceleration of the main motor when one ofthe switch members is moved from initial position. In the application ofRobert C.

Deale, Serial No, 659,339 filed August 25, 1923, is claimed the specifictype of pendent switch mechanism disclosed in this application.

Figure 1 is a front elevational view of a planer adapted to be operatedin accordance with our invention.

Fig. 2 is a diagrammatic view of a control system embodying ourinvention.

Referring to Fig. 1 of the drawing, a planer 1 is shown comprising a bed2 and uprights 3. A table 4, which is mounted on the bed 2, is'operatedby a main motor 5. The main motor 5 is connected to the table rights 3,carries a vtool head 8. A feed motor I ture l6, a series field-magnetwinding 17, a A

4 by means of any suitable gearing 6. A crossrail 7, which is mounted onthe up- 9 is mounted on' the arch which is connected to the twouprights-3. The feed motor 9 erating the pilot switch in one directionand near the end. of the return stroke, the dog 12 engages alever 14 forreversing the position of the pilot switch. The two levers 13 and 14 areconnected to the pilot switch by means of links 15. The dogs 11 and 12may be adjusted along the table 4 to vary the stroke of the planeReferring to Fig. 2 of the drawing. the

'main motor is shown comprising an armashunt field-magnet winding18, acommutator windin 19, and an emergency winding The feed motor comprisesan armature 21, a series field-magnet winding 22, and a shuntfield-magnet winding 23. The main motor 5 is'controlled by two mainswitches 24 and 25 and two acceleratingswitches 26 and 27 The feed motoris controlled by, two feed switches 28 and 29 and an accelerating switch30.

A limit switch 31 is provided for'limiting the feeding movements and aportable switch mechanism 32 is rovided for operating the. main and thefeed motor at will; A suitable circuit'breaker 33 is provided foropening the circuits of the motors upon over-load or under-load circuitconditions. I

.The main switch 24 comprises apivotally mounted switch arm 34 whichcarries two' contact members 35 and 36. The contact member 36 engages astationary contact member 37in the released position of thel switch armand the contact member 35 engages a stationary contact member 38 in theoperative position -of the switch arm. A' mam magnet 39 is provided foroperating the switch arm 34. A holding magnet 40 is provided forpreventing operation of the switch arm 34 when the main switch25 isoperated and also for reventing operation of the switch arm 34 w en adynamic braking current is flowing through the main motor. A switch 41is operated by a pin 42 on the switch arm 34 for inserting a resistor 43in series with a resistor 44 and the shunt field-magnet winding 18whenever the main switch 24 is operated to effect a return -ing throughthe main motor.

tcr electromotive force movement of the planer table. Insertion of theresistors 43- and 44 in circuit with the shunt field-magnet windingeffects a return stroke at a relatively rapid rate. A switch 45 isclosed by the switch arm 34 for completing a circuit to operate theaccelerating switches 26 and 27 under certain conditions The main switch25 comprises a pivotally mounted switch arm 46 which carries two contactmembers 47 and 48. The contact member 48 engages a contact member 49 inthe released position of the switch arm and the contact member 47engages a contact member 50 in the operative position of the switch arm.A main magnet 51 is provided for operating the switch arm. A holdingmagnet 52 is provided for preventing operation of the switch arm 46 whenthe main switch 24 is in an operative position and when a dynamicbraking current is flow- A contact member 53, which is carried by theswitch arm,'engages a stationary contact member 54 when the switch is inan operative position. The contact members 53 and 54 complete a circuitfor operating the accelerating switches 26 and 27. l

The accelerating switch 26 comprises a pivotallymounted switch arm 55which carries a contact member 56 and an insulated contact member 57.The contact member 56 engages a stationary contact member 58 when theswitch arm 55 is in an operative position. The insulated contact member57 bridges contact members 59 and 60 when the switch arm is in areleased position. A magnet 61 is provided for operating theaccelcrating switch in accordance with the coundeveloped by the motor 5.

The accelerating switch 27 comprises a pivotally mounted switch arm 62which carries a contact member 63 and an insulated contact member 64.The contact member 63 engages a stationary contact member 65 when theswitch arm 62 is in an oper- .ative position. The insulated contactmember 64 bridges contact members 66 and 67 when the switch arm is in areleased positlon. A magnet 128 is provided for operat ng the switch arm62. Suitable blow-out coils 68 are provided for extinguishing the arcsformed by the main switches 24 and 25 I and the accelerating switches2.6 and 27.

The pilot switch 10 comprises three contact segments 69, 70 and 71 whichare adapted to engage contact members 72 to 79, inclusive, and a contactmember 160. The limit switch 31 comprises electrically connected contactsegments to 83, inclusive, which are adapted to engage contact fingers84' to 87, inclusive.

The feed switch 28 comprises a switch arm 88 which carries two contactmembers 89 and 90. In the released position of the switch arm, thecontact member 00 engages a stationary contact member 91 and in theoperative position oii the switch arm, the contact member 89 engages astationary contact member 92. A contact member 93, which is mounted onaswitch arm 9%, is operated in accordance with the operation of theswitch .arm 88 to engage a stationary contact member 95. A. magnet 96 isprovided tor efiecting operation of the switch arms 91 and 88 and aholding magnet 07 is provided for preventing operation oi the switcharms when a dynamic braking current is flowing through the feed motor 0.

The feed switch 20 comprises a pivotally mounted switch arm 98 which isconnected. by a link 99 to a pivotally mounted switch arm 100. Theswitch arm 98 carries two contact members 101 and 102 and the switch armcarries acontact member 103. The contact members .101 and 103respectively engage stationarycontact members 104 and 105 when theswitch 29 is in the operative position. The contact member 102 engages astationary contact member 108 when the switch 29 is in the releasedposition. 1 magnet- 107 is provided tor-operating the switch and aholding magnet 108 is provided for; preventing operation of the switchwhen a dynamic braking current is flowing through the motor 0.

The accelerating switch 30 for the feed motor. 0 comprises a pivotallymounted switch arm 103 which carries a contact member 110. The contactmember 110 engages a stationary contact member 111 in the operativeposition of the switch to short circuit an accelerating resistor 112.. Amagnet 113 is provided for operating switch arm 109. Suitable blow-outcoils 11 1 are provided for extinguishing the arcs formed by the contactmembers of the feed switches 28 and 20. A. dynamic braking resistor 115is provided for limiting the braking current flowing through the feedmotor under braking conditions.

Theportable or pendent switch mecha nism 32 comprises two switch members118 and 117 which respectively control the motor 5 and the feed motor9.. The switch members 118 and 11'? not only control the two motors atwill but also prevent operation of the main and the feed motor by thepilot switch and prevent acceleration of the main motor by theaccelerating switches under certain conditions. The switch mem her 116comprises two contact segments 118 and 110 which are adapted to engagecontact members 120 to 12?, inclusive. Tn the position of the switchmemher 110 as shown, the contact segment 118' bridges the contactmembers 121 and 120 for completing a circuit through the magnets 61-and128 of the accelerating switches 20 and 21. The contact segment 119bridges the contact members 122 and 123 for completing a circuit tooperate the main switches 2 1 and 25 and the feed switches 28 and. 29 bymeans oi the pilot switch 10.

The switch member 117 comprises two contact members 129 and 130 whichare adapted to engage contact members 131 to 138, inclusive. The Contactsegment 129 bridges the contact members 131 and 132 tor completing acircuit to operate the acceler ating switches 26 and 27. The contactsegment 130 bridges the contact members 133 and 134- to permit theautomatic operation of the main switches 24 and 25 and the feed switches28 and 29. i

The circuit breaker 33 may be of any suitable type and, as shown,comprises two switch arms 14:0 and 1 1-1 which are adapted to beconnected to the supply conductors 1 12 and 143. An over-load winding16%., and a low voltage winding 1 15 are provided for controlling theoperation of the switch arms 1 10 and 141. A switch arm 146 is providedfor bridging contact members 147.

148, 149 and 150 upon release of the circuit breaker. The switch arm 146serves to complete an emergency braking circuit. An acceleratingresistor 151 is'provided for the main motor 5 and a choke resistor 152 iis provided for the shunt field-magnet winding 18.

During the automatic operation of the system the main motor 5 iscontrolled by the pilot switch 10 and the feed n10tor.0. .is controlledby the pilot switch 10 and the limit switch 31. Near the end of theforward or cutting stroke of the planer, the dog 11 engages the lever 13to operate the pilot switch 10. The contact segment 89 is moved tobridge the contact fingers 78 and/i0. The contact segment '10 is movedto bridge the contact fingers 72 and 'i 3 and the contact segment '11 ismoved to bridge the contact fingers 76 and 160. Upon brit ging thecontact fingers 78 and 79 by the eontact'seg 'ient 60, a circuit iscompleted for energizing the magnet 39 of the main switch 24-. Theenergizing circuit for the magnet extends from the supply conductor 1 3through the switch arm 11-1, series field-magnet winding 17, holdingcoil 52, contact members 18 and 40, switch arm 16, magnetlt), contactlingers 78 and 79, which are bridged by the contact segment 60. contactmembers 133 and 13 1 which are bridged by the contact segment 130,contact lingers 122 and 123. which are bridged by the contact segment119. winding 14 and the switch arm 1. 10 to the supply conductor 1 12.

The main switch 21 is operated and a circuit is completed through themain motor 5 for efi'ecting a return stroke of the planer table. Thecircuit through the main motor extends from the supply conductor 143 bunthrough the switch arm 141, series fieldmagnet winding 17, holding coil52, contact members 49 and 48, switch arm 46,, armature 16, commutatorwinding 19, resistor 151, switch arm 34, contact members 35 and 38,over-load winding 144, and the switch by the contact segment 129,contact members 72 and 73, which are "bridged by contact segment 70, andcommutator winding 19 to the other terminal of the armature 16. Themagnet 128 of the accelerating switch-27 is connected in parallel withthe magnet 61 of the accelerating switch 26. After the operation of theaccelerating switch 26, the accelerating switch 27 is operated for-shortcircuiting all of the resistor 151. In tracing the above circuits, itwill be noted the energizin circuit .for the main magnet 24 is interloced through both of the switch mem-- hers of the pendent switchmechanism. Moreover, the energizing circuit for each of the acceleratingswitches is interlocked through each of the switch members of thependent switch mechanism.

Prior to the operation of the accelerating switch 26, the circuit forthe shunt fieldmagnet winding extends from the supply conductor 143through the switch arm 141, winding 18, contact members 59 and 60, whichare bridged by the contact segment 57, winding 144, and the switch arm140 to the supply conductor 142. The shunt field'- magnet winding 18 isthus connected directly across the suppl circuit. Upon operation of themain swltch 24 and of accelerating switches 26 and 27, the circuit forthe field-magnet winding 18 extends from the supply conductor 143through the switch arm 141, windin 18, resistor 43, resistor 44, winding144, an the switch arm 140 to the l supply conductor142. In case theaccelerating switch 27 has not been operated, the

resistor 44 is short circuited by theswitch member 64 which bridgesthe'contact members 66 and 67. Inasmuch asthe resistors 43 and 44 arebothinclu ded in the circuit of the shunt field-magnet winding, itisapparent the return stroke of the planer table is effected at arelatively rapid rate.

At the same time, as the above operations are effected, the contactsegment 71 bridges the contact fingers 76 and 160 for completing acircuit to operate the feed switch 29. The

through the switch arm 141, series field- I magnet winding 22, magnet107, contact fingers 84 and '85, which are bridged bythe contactsegments 80 and 81, contact fingers 76 and 106, which are bridged by thecontact segment 71,'c0ntact fingers 133-and 134, which are bridged bythe contact segment 130, contact fingers 122 and 123, which are bridgedby the contact segment 119, winding 144, and the switch arm 140 to thesupply conductor 142,

The feed switch 29 is operated for completing a circuit through the feedmotor 9.

The circuit through the feed motor 9 ex-v tends from the supplyconductor 143 through switch arm 141, winding 22, contact members 105and 103, switch arm 100, armature 21, switch arm 98, contact members 101and 104, resistor 112, winding 144, and the switch arm 140 to the supplyconductor 142. The magnet 113 of the accelerating switch 30, which isconnected across the armature 21 of the feed motor 9, is energized tooperate the switch and short circuit the resistor 112. The feed motorcontinues operating until the contact segments 80 and 81 of the limitswitch 31 are separated from the contact fingers 84 and 85. Thereupon,the feed switch 29 is released and a dynamic braking circuit iscompleted through the feed motor. The dynamic braking circuit extendsfrom one terminal of the armature 21 through the contact arm 88, contactmembers 90 and 91, resistor 115, contact members 106 and 102, and switcharin 98 to the other terminal of the armature 21. The holding coils 97and 108 for the feed switches 28 and 29 are connected across the dynamicbraking circuit, and, accordingly, it is impossible to operate either ofthe feed switches until the dynamic braking current ceases to flow.

N ear the end of the return stroke, the dog 12 engages the lever 14 forreversing the position of the pilot switch. The contact segment is movedto bridge the contact fingers 74 and 75, the contact segment 71 is movedto bridge the contact fingers 77 and 160, and the contact segment 69'ismoved to bridge the contact fingers 72 and 7 3. When the contact segment69 is separated from thecontact fingers 78 and 79, the main switch 24 isreleased and a dynamic braking circuit is completed through the mainmotor 5.

of the armature 16, through the switch arm 46, contact members 48 and49, holding coil 52, holding coil 40, contact members 37 and 36, switcharm 34, resistor 151, and the commutator winding 19 to the otherterminal of the armature 16. The holding coils 40 and 59 not onlyprevent operation of the main switches 24 and 25 when a dynamic Thedynamic braking circuit through the main motor extends from one terminalv net 51 of the main switch 25 is contact segment 70 bridging thecontact v is completed through the feed motor 9, which sesame flowingbut also prevent the simultaneous switches. i c

The energizing circuit through the magclosed by the members 74; and 75.The energizing 'circuit for the magnet" 51 extends from the supplyconductor 143 through the switch arm 141, series field-magnet winding17, holding coil 40, contact members 37 and 36, switchnarm 34, magnet51, contact fingers 74 and .75, which are bridged by the contact segment7 0, contact fingers-- 134 I and 133, WlllCh arebridged by thecontactsegment 130, contact fingers 122 and 123, which are bridged bythe contact segments 119,wmding 144, and the switch arm 140 to thesupply conductor 1 42.

The main switch 25 is operated and a circuit is completed through themain motor 5, which extends fromthe' supply conductor 142 through theswitch arm 141, series fieldmagnet winding 17, holding coil 40, contactfingers 37 and 36, switch arm 34, resistor 151, commutator winding 19,armature 16, switch arm 46, contact members 47 and 50, winding 144 andswitch arm 140' to the supply conductor 142. The main motor 5 isoperated in a direction to effect a cutting stroke by the planertable'4. The accelerating switches 26 and 27 are operated forshortcircuiting the resistor 151. The energizing circuit for suchaccelerating switches extends from one terminalof the armature 16through switch arm 46, contact members 53 and 54, magnets 61 and 128 ofthe accelerating switches 26 and 27 in parallel, contact members 120 and121, which are bridged by the contact segment 118, contact members 131and 132, which are bridged by the contact segment 129, contact fingers72 and 73, which are bridged by the contact segment 69, and thecommutator winding 19 to the other-terminal or the an mature 16.

Upon operation or" the accelerating switches 26 and 27, the circuitthrough the shunt field magnet winding 18 extends from the supplyconductor 143 through switch arm 141, winding 18, resistor 43, switch41, winding 144 and the switch arm 140 to the supply conductor 142.During the cutting stroke of the planer, the resistor 44 is not includedin the circuit of the shunt fieldmagnet winding, and, consequently thespeed of the main motor is reduced.

Y The magnet of the feed switch 28 is energized by a circuit whichextends from the supply conductor 143 through the switch arm 141, seriesfield-magnet winding 22, magnet 96, contact fingers 86 and 87, which arebridged by the contact segments 82 and 83, contact fingers 77 and 160,which are bridged by the contact segment 71, contact 'the pendent switchmechanism,

fingers 133 and 134, which are bridged by the contact segment 130,contact fingers 122 and 123,

which are bridged by the contact segment 119, winding 144, and theswitch arni 140 to the supply conductor 142.

The switch 28 is operated and a circuit extends from the supplyconductor 143.

through the switch arm 141, series field-magnet winding 22, contactmembers 95 and 93,

switch arm 94, armature 21, switch arm 8.8,

contact members 92 and 89, resistor 112,

winding 144and the switch arm 140 to the supply conductor 142. The feedmotor 9 is operated in a reverse direction. The accelcrating switch 30isoperated for short circuiting the resistor 112.

associated with the niain motor and the energizing coils for the twofeed switches and for the two main switches are interlocked through bothof the switch members 116 and 117 of the pendent switch mechanism 32.The switch member 116 of the pendent switch mechanism 32 controls theoperation of the main motor 5 at will and the switch member'117 of thependent switch controls the feed motor 9 at will. In order to effectoperation of the main motor 5 by the switch member 116 is movedupwardly, as shown in Fig. 2 of the, drawing, to disenga e the contactsegment 118 from the contact 'ngers v 120 and 121 and to disengage thecontact segment 119 from the contact fingers 122,

and 123. The separating of the contact segment 118 from the contactfingers 129 and 121 prevents any operation of the accelerating switches26 and 27." The separating of the contact segment 119 from the contactringers 122 and 123 prevents any operation 7 of the main switches 24 and25 and the feed switches 28 and 29 by the pilot switch 10. The switchmember 116 is then given a movement of rotationin. one direction'or theother to bridge thecontact segments 124' and 126 by the contact segment119 or to bridge the contact members and 127 by the contact segment119.The bridging of the contact members 124 and 126 by the contact segment119 operates the main switch 24 ror effecting a return movement of theplaner table. The energizlng circuit for the main switch extends fromthe supply conductor 143 through the switch arm 141,

series field-magnet winding 17, holding coil 52, contact members 49 and48, switch arm 46, magnet 39, contact fingers 124 and 126,

' members 136 and which are bridged by the contact segment 119, winding144, and the switch arm 140 to the supply conductor 142.

When the contact segment 119 bridges the contact members 125 and 127, acircuit is completed which extends from the supply conductor 143,through the'switch arm 141, series field-magnet winding 117, holdingcoil 40, contact members 37 and 36, switch arm '34, magnet .51, contactmembers 125 and 127, which are bridged by the contact segment 119,winding 144 and the switch arm 140 to the supply conductor 142. The mainswitch 27 is closed and the motor 5 is operated in a direction to effecta cutting stroke by the planer table.

The switch member 117, which controls the feed motor 9, is movedupwardly, as

shown. in Fig. 2 of the drawing, to prevent operation of theaccelerating switches 26 and 27, and to prevent operation of theswitches 24, 25, 28 and 29 by. the pilot switch 10. In order to effectoperation of the feed motor 9 in one direction by the feed switch 28,the switch member 117 is turned... to bridge the contact fingers 135 and137 by the contactsegment 130. The energizing circuit for the feedswitch 28 extends from the supply conductor 143 through the switcharm141, winding 22, magnet 96, contact fingers 135 and 137, which arebridged by the contact segment 130, winding 144, and the switch arm 140to the supply conductor 142.

In order to effect operation of the feed motor in a reverse direction,the switch member 117 is moved to bridge the contact 138 by the contactsegment 130. A circuit is completed for operating the feed switch 29.The energizing circuit for the feed switch 29 extends'from the supplyconductor 143 through the switch arm 141, the winding 22, magnet 107,contact'members 136 and 138, which are bridged by the contact segment130,winding 144, and the switch arm 140 to thesupply conductor 142. Thecircuits completed through the feed motor were traced in describing theautomatic operation thereof by the pilbt switch 10.

Modifications in the system and in the arrangement and location of partsmay be made within the spirit and scope of our in-' vention and suchmodifications are intended to be covered by the appended claims.

What we claim is:' 1; In a control system for a machine tool,

thecombination with a reciprocating member, a main motor for operatingsaid reciprocating member, a cutting tool, and a feed motor foroperating the cutting tool with respect to the reciprocating member, of

trolling the operation of the main motor at will and having a secondswitch member for controlling the operation of the feed motor at will.

2. In a control system for a machine tool, the combination with areciprocating member, a main motor for operating said reciprocatingmember, two main switches for operating the main motor in a forward andin a reverse direction and for completing a dynamic braking circuittherethrough, a feed motor, and two feed. .switches for controlling theoperation of the feed motor, of means comprising a portable switch mechanism having two switch members for respectivelycontrolling theoperation of the main and feed switches at will.

3. In a control system for a machine tool, the combination with areciprocating member, main motor for operating said reciprocatingmember, a cutting tool, and a feed motor for operating the cutting toolwith respect to the reciprocating member, of means comprising a portableswitch mechanism having two switch members for respectively controllingthe operation of the main and feed motors at will, andmeans forautomatically operating the main and the feed motor in accordance withthe movement of the reciprocating member.

4. In a control system for a machine tool, the combination witha-reciprocating member, a main motor for operating said reciprocatingmember, two main switches for operating the main motor in a forwardandin a reverse direction and for completing a dynamic braking circuittherethrough, a feed motor, and two feed switches for controlling theoperation of the feed motor, of means comprising a portable switchmechanism having two switch members for respectively controlling theoperation of the main and the feed switches at will, and means forautomatically operating the main and the feed switches in accordancewith the movement of the reciprocating .member.

5. In a control system for a machine tool, the combination with areciprocating member, a main motor for operatmg the reciproeatingmember, and a feed motor, of means for automatically operating the mainand feed motors, and means comprising a single portable switch mechanismhaving two switch members for respectively operating the main and thefeed motors at will.

6. In a control system for a machine tool,

the combination with a reciprocating member, a main motor for operatingthe reciproeating member, and a feed motor, of means controlled by thereciprocating member for automatically operating the main and the feedmotor, means comprising a portable switch mechanism having two switchmemanism having means celeration of the feed motor,

bers i'or respectively operating the main and the feed motor at will,and means for preventing the automatic operation of the main and thefeed motor when one of said switch members is operated.

7. In a control system for a machine tool, the combination with areciprocating member, a main motor for operating said reciprocatingmember, and a feed motor for operating the cutting tool with respect tothe reciprocating member, of means for automatically operating the mainand the feed I motor in accordance with the operation of thereciprocating member, and means comprising a portable switch mechanismhaving two switch members for respectively operating the main and thefeed motor at will, said portable switch having means for preventing theautomatic operation of the main and the feed motor when one of saidswitch members is operated.

8. In a control system for a machine tool, the combination with areciprocating member, a main motor for operating the reciproeatingmember, two main switches for operating the main motor in a forward andin a reverse direction and for completing a dynamic braking circuittherethrough, a feed motor, and two feed switches for controlling theoperation of the feed motor, of means forautomatically operating themain and the feed switches in accordance with the movement-of thereciprocating member, and means comprising aportable switch mechanismhaving two switch members for respectively operatin the main and thefeed motor at will, sai portable switch mechfor preventing the automatic operation of the main and the feed motor when one of said switchmembers is operated.

'9. In a control system for a machine tool, the combination with areciprocating member, a main motor for operating the reciproeatingmember,

a feed motor, and two feed switches for operating the feed motor, ofmeans for automatically controlling the two iced switches by thereciprocating member to efiect operation of the feed motor in oppositedirections at opposite ends of the movement of the reciprocating member,and a portable switch for operating the feed switches at will whilereventing operation of the feed switches by the means automaticallycontrolled by the reciprocating member.

10. In a control system for a machine tool, the combination with areciprocating member, a main motor for operating the reciprocatingmember, a feed motor, two feed switches for operating the feed motor,and an accelerating switch for governing the acof means forautomatically controlling the two feed switches by the reciprocatingmember to effect operation of the feed motor in opposite directions atopposite ends of the movement ofthe reciprocating member, and a portableswitch for preventing operation of the two feeding switches and theaccelerating switch by said automatic means under certain conditions andfor operating the feed switches at will.

11. In a control system for a machine tool, the combination with areciprocating memher, a main motor for operating the reciprocatingmember, a feed motor, and two feed switches for operating the feed motorin a forward and in a reverse direction and for completing a dynamicbraking circuit therethrough, of means for automatically controlling thetwo feed switches in accordance with the operation of the reciprocatingmember, and a portable switch for preventing operation of the two feedswitches by said automatic means and for operating the feed switches atwill.

12. In a control system for a machine tool, the combination with areciprocating member, a main motor for operating the reciprocatingmember, a feed motor, and two feed switches for operating the feed motorin a forward and in a reverse direction and for completing a dynamicbraking circuit therethrough, each of said feed switches having aholding coil for preventing the operation of the switch when a dynamicbraking current is flowing through the feed motor, of means forautomatically controlling the two feed switches in accordance with theoperation of the reciprocating member, and a portable switch forpreventing operation of the two feed switches by said automatic meansand for operating the feed switches at will.

13. In a control system for a machine tool, the combination with areciprocating member, a main motor for operating the reciprocatingmember, two main switches for operating the main motor in a forward andin a reverse direction and for completing a dynamic braking circuittherethrough, a feed motor, two feed switches for operating the feedmotor verse direction and for completing a dy namic braking circuittherethrough, and a pilot switch operated by the reciprocating. memberfor automatically controlling the main and the feed switches,"of aportable switch mechanism having two switch mem- 1 bers for respectivelycontrolling the main and the feed motors at will, each of said switchmembers having an interlock iotpreventing the automatic operation of themain and the feed conditions.

14. In a control system for a machine tool, the combination with areciprocating member, a main motor for operating the reciproeatingmember, two main switches for operswitches under certain 1 in a forwardand in a reating the main motor in a forward and in a reverse directionand for completing a dynamic braking circuit therethrough, anaccelerating switch for said main motor, a feed motor, two feed switchesfor operating the feed motor in a forward and in a reverse direction andfor completing a dynamic braking circuit therethrough, an ac celeratingswitch .for said feed motor, and means for automatically operatingthe'main and the feed switches in accordance with the operation or" thereciprocating member, of a portable switch mechanism having two switchmembers for respectively controlling the main and the feed motors atwill, each of said switch members having. interlocks for preventing theautomatic operation 01' the main and the feed switches in accordancewith the operation of the reciprocating member and for preventingoperation of the accelerating switches.

In testimony whereof, we hereto affix our signatures.

ROBERT C. DEALE. HAROLD L. BLOOD

